E5420 Internal Mic not showing up in device manager

I have an E5420 runnning Windows 7 64 bit. The BIOS shows that the internal microphone is activated but it does not show up in the device manager nor does it show up when looking in the recording devices window. In the device manager there are two High Definition Audio Devices installed, but looking at the properties of them one seems to point to the right side jack (a combo jack) and the other to the left side jack which does not physically exist. There is one item in the device manager under Other devices listed as an Unknown Device.

The microphone for this computer model is optional. I am sending you a private message. Please respond with the system Service Tag and your name so that I can check the system details and assist you further. If you sure about the fact that the laptop was bought with a preinstalled microphone, then you can try the following steps: Note: Microphones do not show up in Device Manager.

Ensure that microphone is enabled in ‘Recording Devices’

Open ‘Recording Devices’ window

Right click on the empty space, choose ‘Show Disabled Devices’

If microphone shows up, then right click on ‘Microphone’

Choose ‘Enable’

Restart the computer

If the above steps do not work, then try the following steps:

Check with external headsets

If external headset and the internal microphone does not work, then

Click on ‘Start’

Click on ‘Accessories’

Click on ‘Sound Recorder’

Click on ‘Start recording’ (record your voice for about 2-4 minutes)

Click on ‘Stop Recording’, save the file on the desktop

Play the saved file and check if its working

If external headsets do not work, uninstall and reinstall updated drivers: